The present invention relates in general to the design of golf clubs and in particular to the design of putters and a manufacturing method to insure that a true balance is achieved notwithstanding minor tolerance variations which typically occur during the manufacturing process.
The designs of golf clubs over the years have focused on numerous concepts which were believed to provide longer shots, more accurate shots, better control, better feel, more power and so forth. Quite often the design changes have involved a change of materials. Wooden shafts have given way to metal and now graphite. The heads of the woods and irons have undergone material changes as well as weight-distribution and shaping changes. These design evolutions have not been limited to the woods and irons, putters have seen as much if not more changes in their shapes and design theories over the years as any of the other clubs. One possible explanation for the extensive activity in the design of golf putters is the significance of this particular club relative to the other clubs when one considers the stroke count in a typical par round of golf. While the driver will typically be used 14 times and a 3-wood 4 or 5 times, other clubs such as the various irons may only be used a maximum of 4 or 5 times in any one round of golf. The putter, on the other hand, is used at least 24 times and more likely 36 times (or more), assuming that for a par round the golfer reaches each green in regulation and is able to two-putt each green.
While the design change activities for golf have been directed to literally all phases of the game, including golf balls, not all design changes are good for all players because of physical differences and styles. Due to anatomical differences in players and the dynamics of their style of play, certain changes which have been made to the woods and irons are not well suited to every player. Consequently, numerous changes and variations have been offered by literally every manufacturer in an attempt to find a particular combination of features and design style which a large number of players like and hopefully prefer. The problem is that there is no common denominator as to a feature or features which everyone agrees is an absolute necessity. Some players still prefer metal shafts over graphite and some players still prefer laminated wood over metal heads for the driver and 2-5 "woods". The reason these players prefer the "older" design style is that they play better with these styles. Most golfers are not so vain as to stick with a wood or iron style for sentimental reasons if it is adversely affecting their play. Golfers, like most other sportsmen, continually look for the newest or latest development in hopes that the design changes will improve their game not only for a lower score but as well for the satisfaction of a well-struck shot and the enjoyment which that gives to a golfer. The level of play is all that matters to professional golfers, and thus if there was clearly a superior design style everyone would go to that style and yet, as we know, this has not occurred.
While there is no common denominator for an essential design feature for woods or irons outside of the basics of a shaft and head and the necessary size and weight, there is a key or critical ingredient to the design of the best golf putter, and this ingredient is for the putter to possess a true balance. A putter's performance does not improve by the use of space age manufacturing techniques directed to shaping the head or extruding the shaft, etc. What really matters in the design of a golf putter is its balance. Only with a near-perfect or true balance can the golfer's success be controlled solely bv the golfer's abilities. If a highly skilled golfer uses a putter which is not properly balanced, the putter will react by tending to turn or shift and while the golfer can manually override this tendency, it does influence the golfer's control, swing, and aim. In other words, can the golfer determine how much to alter or compensate an otherwise true swing or stroke in order to take into consideration the inherent turn or shift in the putter which results when the putter is not properly balanced?
If one looks at those putters with odd-looking, peculiar shapes, it should be clear that what the designer is trying to do is use shaping and weighting theories to try and achieve a true or perfect balance. In some instances, the shaping and styling of the putter is done with the objective of enhancing the golfer's aim, feeling that if the golfer is able to maintain the putter in a particular direction during the swing, assuming that direction has been predetermined as a proper direction, then the resultant stroke will be somewhat more accurate. The problem though persists in that as the golfer swings the putter, if the putter is not properly balanced, it will tend to turn or pivot in the golfer's hands and the golfer must adjust and compensate for this tendency. Numerous attempts have been made to try and guarantee the golfer a true and accurate swing, but how can this be done if the putter has a tendency to rotate or turn during a free swing such that the ball-striking face is not properly oriented at the point of contact?. One problem in the past is that different manufacturers have different theories as to balance and while some degree of balance might exist in one plane or orientation for the putter, the dynamic balance of the putter swing has been ignored.
In U.S. Pat. No. 4,866,979, which issued Sep. 19, 1989 to Bernhardt, an apparatus is disclosed which is designed to reveal the true balance of golf putters as they swing in a manner which accurately simulates a putter stroke. The putter under examination is installed into a holder which is set at an inclined angle and pivotally attached to an upright support. As the putter is drawn up and away, and then released and swings, if true balance does not exist the putter will turn or rotate in the holder, thereby revealing the fact that the putter is not balanced in the only mode of balance that really matters, namely dynamic balance during the swing or stroke motion.
This balance-revealing device for golf putters has been successfully used by pro shops and by companies in order to compare the balance of various putters. Various putters which the designer, manufacturer, or user may have claimed to be balanced have been shown to be unbalanced by this apparatus. This unbalanced condition is disclosed during the simulated putter stroke by the putter actually turning in the apparatus as is fully described in U.S. Pat. No. 4,866,979. What happens is that at the point of contact with the ball, the putter head is oriented in a totally unacceptable position and use of this invention allows one to compare the degree of balance of various competing putters.
Since achieving a true balance for golf putters is important regardless of personal preferences in the size and shape of the putter head and regardless of the stroke style, it is important to be able to control the balance during the manufacturing process. While the balance-revealing apparatus invention will tell when the manufacturing process has failed, it is then too late. Further, even a precisely dimensioned and styled putter can encounter minor variations in weight distribution due to casting tolerances, porosity, etc. which will throw off the anticipated balance or center of gravity.
In order to try and achieve a true balance golf putter, a manufacturing method has been conceived wherein various geometric cutting planes are used to divide the putter head. This invention is disclosed in U.S. Pat. No. 5,228,332 which issued Jul. 20, 1993 to Bernhardt. In this invention one cutting plane divides the head through the center of gravity between the top and bottom. Another cutting plane divides the putter head through the center of gravity between the heel and toe. The final cutting plane divides the head through the center of gravity between the front surface and rear surface of the putter head. In the '332 patent, the point of attachment of the shaft neck is centered on the cutting plane dividing the head between the front and rear surfaces. With this point of attachment, the axis of the shaft is directed so as to extend along the front to rear cutting plane and pass near the overall center of gravity, but not through the overall center of gravity.
According to the present invention it has been learned that it is not necessary to center the point of attachment for the shaft neck on the geometric cutting plane which extends through the front-to-rear center of gravity. Proper alignment and balance can still be achieved by being prepared to bend the shaft neck at one or two spaced-apart locations in order to orient the longitudinal shaft axis so as to extend in the desired direction. The desired direction is a direction which passes beside the overall center of gravity and is spaced from the overall center of gravity by a designed dimension (i.e., distance 42 in the '332 patent).
The present invention also discloses a manufacturing method similar to that of the '332 patent which enables one to adjust the relationship of the head and shaft in order to compensate for minor tolerance and weight distribution variations which, if left alone, would create an unbalanced putter. In the manufacture of golf putters, once the shaft is rigidly fixed to the putter head, precise adjustments cannot be made in any realistic fashion or manner.